1. Field of the Invention
The present general inventive concept relates to a solid ink jet printer, and more particularly, to a heating apparatus for the solid ink of a solid ink jet printer, which is provided with a heating plate having an improved structure for heating the solid ink.
2. Description of the Related Art
When Tektronix, Inc. introduced a Tektronix Phaser® III color printer in 1991, a solid ink printing technology could be successfully commercialized. This technology employs a special ink jet printhead that is rapidly shuttled back and forth to spray ink directly onto a page as in most of recent ink jet printers. The ink used therein is solid at room temperature, and is melted and kept at about 140° C. in the printhead. The solid ink, e.g., a color stick, is durable and is usable for rapid printing operations, generating vivid color on almost all kinds of paper including expensive office bond paper and recycled paper.
Unlike other related printers, in which operation of the printer must stop when printing raw materials (e.g., ink) run out in order to replace the printing raw materials, it is possible to input the solid color stick in the Tektronix printer during the operation of the printer. Further, mass production of the solid color stick is easy since a separate cartridge for containing the ink is not necessary. In addition, a solid crayon material, i.e., an ink raw material, is very inexpensive. Therefore, when compared with a laser printer, a purchase cost of the solid ink jet printer is 12˜20% less than a purchase cost of the laser printer, and a maintenance cost of the solid ink jet printer is one half of a maintenance cost of the laser printer.
FIG. 1 is a view illustrating a configuration of a solid ink feed part of a conventional solid ink printer disclosed in U.S. Pat. No. 5,784,089, and FIG. 2 is a perspective view illustrating a configuration of an ink stick storage part of the solid ink printer.
Referring to FIGS. 1 and 2, an ink stick feed apparatus includes an ink stick loading bin assembly 16, a yoke 17, a top cover 20 and an ink stick feed cover 30.
The ink stick loading bin assembly 16 for storing ink sticks 12, for example, according to their colors, and for moving the ink sticks 12 toward heating plates 29a to 29d, has feed chutes 25a to 25d and a key plate 18 covering the feed chutes 25a to 25d. In the key plate 18, openings 24a to 24d, through which the ink sticks 12 are inserted, are formed.
The top cover 20 is pivotally mounted to open and close an upper portion of the key plate 18. The ink stick feed cover 30 is pivotally mounted to sidewalls 21 through a pair of pivot arms 22. The yoke 17 is mounted on top of the key plate 18 and is slidable along the top of the key plate 18 to assist in moving the individual ink sticks 12 forward in the feed chutes 25a to 25d toward the heating plates 29a to 29d. 
The ink sticks 12 are inserted through the openings 24a to 24d of the key plate 18 corresponding to the feed chutes 25a to 25d to be melted by the heating plates 29a to 29d and to flow into individual ink reservoirs (not illustrated) of a printhead 70 (see FIG. 3).
The heating plates 29a to 29d are attached to one end portion of the ink stick loading bin assembly 16 by a melt plate adapter assembly 27.
FIG. 3 is a view illustrating the ink stick feed part 16 and the printhead 70 in accordance with the prior art, and FIG. 4 is a front view illustrating a configuration of the heating plates 29a-29d in accordance with the prior art.
Referring to FIG. 3, the ink stick loading bin assembly 16 is disposed above the printhead 70. On one end portion of the ink stick loading bin assembly 16, the heating plates 29a to 29d for the individual colors, i.e., cyan, magenta, yellow and black, are fixed by wire springs 73a to 73d. 
Referring to FIG. 4, on the heating plates 29a to 29d, heating lines 75a to 75d electrically generating heat are formed. And to the heating lines 75a to 75d, input and output wires 77a and 77b supplying power thereto are connected. Further, on one side of the heating plates 29a to 29d, temperature detecting sensors 81a to 81d to detect temperatures of the heating plates 29a to 29d are provided. And to each of the temperature detecting sensors 81a to 81d, a pair of wires 83a and 83b are also connected.
However, there is a drawback in the prior art described above; since the heating plates 29a to 29d are formed as a plurality of separate heating plates, and since the heating plates 29a to 29d are each fixed by the individual wire springs 73a to 73d, assembly is difficult and a cost is increased.
Further, there is another drawback; since the input and output wires 77a, 77b supplying power to the individual heating lines 75a to 75d are provided separately, the number thereof is as much as eight and thus the cost is further increased.